Because of some turbulence in real life (™) over the last few months, it’s been somewhat hard to concentrate on research. Fortunately the obligation of teaching sometimes exerts the right sort of psychological pressure to keep my mind on mathematics in short bursts. 2,283 more words

## Tags » 3-manifolds

#### Not all finitely-presented groups are fundamental groups of closed 3-manifolds

In our previous note Amalgamated products and HNN extensions (IV): Markov properties, we saw that for every and for every finitely-presented group , there exists a -dimensional closed manifold whose fundamental group is . 1,254 more words

#### MOO is classical

The simplest quantum 3-manifold invariant is the Murakami-Ohtsuki-Okada (MOO) invariant. It comes from Chern-Simons theory in the way that the Reshetikhin-Turaev invariant comes from Chern-Simons Theory. 1,270 more words

#### SnapPy 2.3 released

Marc Culler and I are pleased to announce version 2.3 of SnapPy. New features include:

- Major improvements to the link and planar diagram component… 100 more words

#### Complex hyperbolic geometry of knot complements

This morning there was a paper which caught my eye:

324 more wordsDeraux, M. & Falbel, E. 2015 Complex hyperbolic geometry of the figure-eight knot.

Geometry & Topology…

#### Mr Spock complexes (after Aitchison)

The recent passing of Leonard Nimoy prompts me to recall a lesser-known connection between the great man and the theory of (cusped) hyperbolic 3-manifolds, observed by my friend and former mentor Iain Aitchison. 993 more words

#### Taut foliations and positive forms

This week I visited Washington University in St. Louis to give a colloquium, and caught up with a couple of my old foliations friends, namely Rachel Roberts and Larry Conlon. 1,878 more words